1. Field of the Invention
This invention relates to a keyboard assembly for electronic musical instruments, which is provided with mass members each driven as a corresponding key is depressed, and detecting means for detecting a state of key depression, the keyboard being associated with an electronic musical instrument such that the latter generates musical tones in accordance with the detected state of the key depression.
2. Prior Art
Japanese Laid-Open Patent Publication (Kohyo) No. 56-500055 discloses a keyboard assembly for electronic musical instruments, which is provided with mass members each driven as a corresponding key is depressed, and detecting means for detecting a state of key depression, the keyboard being associated with an electronic musical instrument such that the latter generates musical tones in accordance with the detected state of the key depression.
FIG. 15 is a side view showing a structure of a combination of a single key with an electronic signal output unit in the above conventional keyboard assembly.
As shown in the figure, a jack 202 is provided on a rear end of a key 201 to push a mass member 203 upward, and a spring arm 204 is fixed at one end thereof to a rear end of the mass member 203, in a fashion extending from the rear end of the mass member 203. The spring arm 204 has a roller 205 attached to the other end thereof. The roller 205 is urged against a switch plate 207 which has an upper pressure-sensitive layer 206 to be urged by the roller 205.
When the key 201 is depressed, the mass member 203 is pushed upward by the jack 202, whereby the roller 205 urgingly slides on the switch plate 207 downward until the mass member 203 comes into contact with an arm stopper 208.
This conventional keyboard assembly is constructed such that key depression is not detected in regions close to the start and end points of a key stroke, because such regions are susceptible to erroneous touch and rebound, making the detection of key depressing operations unstable, but key depression is detected during a time period from a time point when the roller 205 reaches a first contact having a certain width and located at a substantially central portion of the switch plate 207 to a time point when the roller 205 reaches an initial end of a second contact having a certain width and also located at the substantially central portion of the switch plate 207.
According to the conventional keyboard assembly, however, key depression is detected only within the region located at the substantially central portion of the switch plate 207 as described above. Thus, when a single key is successively depressed to repeatedly generate the same tone, it is necessary to provide a deeper key stroke than that of a keyboard assembly for an acoustic piano, and a player feels uncomfortable with such a deep key stroke.
Further, for the same reason, the convectional keyboard assembly is not capable of detecting such a key depression as to generate musical tones in a wide dynamic range.
If the region for detecting key depression is increased, it seems that the conventional keyboard assembly will have a key stroke during successive key depressions closer to that of a keyboard assembly for an acoustic piano so that it is possible to detect a key depression having a wide dynamic range.
However, in the conventional keyboard assembly, the region for detecting key depression is required to be limited as mentioned above for the following reasons: (1) when an initial end of the first contact is changed to a shallower position in the key stroke, a key depression starts to be detected even when the key 201 is slightly touched, and conversely, when the initial end of the second contact is changed to a deeper position in the key stroke, the detection of the key depression is not completed unless the key 201 is depressed to the full degree; and (2) when the key 201 is hit strongly, the mass member 203 collides with the arm stopper 208 to become stopped, but at this moment, a felt part of the arm stopper 208 collapses and then recovers, and if the key is then kept depressed, the felt part becomes slightly collapsed again, and this causes the roller 205 to move to and fro (i.e. rebound) on the switch plate 207, and hence occurrence of chattering of the key due to rebound of the roller 205 must be suppressed.
Further, in the conventional keyboard assembly, the key depression/release operation timing and the tone generation/damping timing are slightly different from each other so that it is difficult to express delicacy as in acoustic pianos, particularly, grand piano.
It is a first object of the present invention to provide a keyboard assembly for an electronic musical instrument, which is capable of having touch inputs to a key from a finger of a player reflected in his power of expression with higher fidelity even when the single key is successively depressed to repeatedly generate the same tone.
It is a second object of the present invention to provide a keyboard assembly for an electronic musical instrument, which is capable of allowing the musical instrument to express delicacy as in acoustic pianos, particularly, grand piano.
To attain the first object, in a first aspect of the present invention, there is provided a keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of musical tone instruction devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein the musical tone instruction devices each comprise a first sensor and a second sensor for generating a key event during a stroke of the corresponding one of the keys in response to depression of the corresponding one of the keys or in response to pivotal movement of a corresponding one of the mass members responsive to the depression of the corresponding one of the keys, the first sensor being disposed to be activated in a first half of the stroke of the corresponding one of the keys to determine timing for damping of the musical tone, the second sensor being disposed to be activated in a second half of the stroke of the corresponding one of the keys to determine timing for generation of the musical tone, the second sensor further determining timing for determining a velocity of the corresponding one of the keys depending on a position of the corresponding one of the keys during the stroke relative to the support device.
The term xe2x80x9cfirst half and second half of the key strokexe2x80x9d used herein does not mean a first half and a second half obtained by equally dividing the key stroke, but means more broadly, i.e. a first half and a second half obtained by dividing the key stroke at a desired ratio.
Further, the first and second sensors may be touch sensors or full-stroke sensors. When the full-stroke sensors are used, values detected during part of the full key stroke are used to determine the respective kinds of timing referred to above.
According to the arrangement of the first aspect, the first sensor which is activated in the first half of the key stroke determines the timing for damping a musical tone, and the second sensor which is activated in the second half of the key stroke determines not only the timing for generating a musical tone, but also the timing for determining the velocity of the corresponding one of said keys depending on the position of the corresponding key during the stroke relative to the support device. Therefore, to repeatedly generate the same tone, the key stroke need not extend to a position corresponding to the tone damping timing in the first half of the key stroke, but has only to extend to a position corresponding to predetermined timing in the latter half of the key stroke. Thus, the same musical tone can be repeatedly generated with ease. As a result, even when a player successively depresses the key to repeatedly generate the same tone, such successive touch inputs to the key from his finger can be reflected in his power of expression with higher fidelity.
To attain the first object, in a second aspect of the invention, there is provided a keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of sensor devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein the sensor devices each comprises a first position signal generator driven in a second half of a stroke of a corresponding one of the keys, for generating a first position signal indicative of a first position of the corresponding one of the keys in which an instruction for generation of a musical tone is to be given during depression of the corresponding one of the keys, when the corresponding one of the keys is located in the first position, a second position signal generator driven in the second half of the stroke of the corresponding one of the keys, for generating a second position signal indicative of a second position of the corresponding one of the keys in which a measurement of a depression velocity of the corresponding one of the keys is to be started during depression of the corresponding one of the keys, when the corresponding one of the keys is located in the second position, and a third position signal generator driven in a first half of the stroke of the corresponding one of the keys, for generating a third position signal indicative of a third position of the corresponding one of the keys in which an instruction for damping the musical tone is to be given during release of the corresponding one of the keys, when the corresponding one of the keys is located in the third position, the mass members being each arranged relative to the support device such that a limit position of the corresponding one of the keys in which the musical tone can be repeatedly generated due to a rebound of the mass member during generation of the musical tone is located farther from a position of the corresponding one of the keys in a released state than the second position.
According to the arrangement of the second aspect, the mass members are each arranged relative to the support device such that the limit position of each key in which a musical tone can be repeatedly generated due to a rebound of the mass member during generation of the musical tone is located farther from a position of the key in a released state than the second position. Therefore, occurrence of chattering during repeated generation of a musical tone can be suppressed, enabling the player to repeatedly generate the same tone easily. As a result, even when the player successively depresses a key to repeatedly generate a single tone, such successive touch inputs to the key from his finger can be reflected in his power of expression with still higher fidelity.
To attain the first object, in a third aspect of the invention, there is provided a keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of musical tone instruction devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein the musical tone instruction devices each comprise a first touch sensor and a second touch sensor that generate a key event during a stroke of the corresponding one of the keys in response to pivotal movement of a corresponding one of the mass members responsive to depression of the corresponding one of the keys, the first and second touch sensors each having a moving part and a fixed part, the second touch sensor being disposed to be activated in a second half of the stroke of the corresponding one of the keys, for generating a first timing related to musical tone generation, and a second timing related to musical tone generation corresponding to a shallower position of the corresponding one of the keys during the stroke than the first timing, the first touch sensor determining timing related to musical tone damping corresponding to a shallower position of the corresponding one of the keys during the stroke than the first timing, the moving part of at least one of the first and second touch sensors being driven by the corresponding one of the mass members, and the fixed part of the first touch sensor and the fixed part of the second touch sensor being arranged respectively on separate boards.
According to the arrangement of the third aspect, the movable part of at least one of the first and second touch switches is driven by a corresponding mass member. Therefore, the detection stroke can be made larger in terms of hammer stroke while it is kept smaller in terms of key stroke. This improves the sensing resolution of the detection stroke. Further, the fixed parts of the first and second touch switches are located on respective separate boards. Therefore, the degree of freedom in arranging the these switches is increased, which in turn increases the degree of freedom in improving the sensing resolution.
To attain the second object, in a fourth aspect of the present invention, there is provided a keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of musical tone instruction devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein one of the first sensor and the second sensor is activated by the corresponding one of the keys, and the other is activated by the corresponding one of the mass members.
According to the arrangement of the fourth aspect, one of the first sensor and the second sensor is activated by a corresponding key, and the other is activated by a corresponding mass member. Therefore, key events are generated during the stroke of the key in response to outputs from the sensors. As a result, it is possible to more accurately simulate tone generation timing and tone damping timing when keys of a keyboard of an acoustic piano, particularly a grand piano are depressed and released, thus allowing the musical instrument to express delicacy as in a grand piano.
The keyboard assembly for electronic musical instruments according to the present invention is not limited to the above described constructions, and further may be constructed as follows, for example:
A keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of musical tone instruction devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein the musical tone instruction devices each comprise a first sensor and a second sensor for generating a key event during a stroke of the corresponding one of the keys in response to depression of the corresponding one of the keys or in response to pivotal movement of a corresponding one of the mass members responsive to the depression of the corresponding one of the keys, the first sensor being disposed to be activated in a first half of the stroke of the corresponding one of the keys to determine timing for damping of the musical tone, the second sensor being disposed to be activated in a second half of the stroke of the corresponding one of the keys to determine timing for generation of the musical tone, the second sensor further determining timing for determining a velocity of the corresponding one of the keys depending on a position obtained by calculating a position of the corresponding one of the mass members during a depression stroke relative to the support device in terms of a position of the corresponding one of the keys.
A keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of musical tone instruction devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein the musical tone instruction devices each comprise a first sensor and a second sensor for generating a key depression event or a key release event during a stroke of the corresponding one of the keys in response to depression of the corresponding one of the keys or in response to pivotal movement of a corresponding one of the mass members responsive to the depression of the corresponding one of the keys, the first sensor being disposed to be activated in a first half of the stroke of the corresponding one of the keys to detect a third position which is a position of the corresponding one of the keys assumed during release, the second sensor being disposed to be activated by the corresponding one of the mass members in a second half of the stroke of the corresponding one of the keys to detect a first position which is a position of the corresponding one of the keys assumed during depression, and detect a second position which is closer than the first position and farther from a position of the corresponding one of the keys in a released state than the third position, the musical tone instruction devices each instructing generation of a corresponding musical tone when the second sensor detects the first position after detecting the second position, and preparing regeneration of the corresponding musical tone when the second sensor again detects the second position while generation of the corresponding musical tone is instructed.
A keyboard assembly comprising a plurality of keys, a plurality of mass members each disposed to be pivotally driven in response to depression of a corresponding one of the plurality of keys, a support device that pivotally supports the plurality of keys and the mass members corresponding respectively to the keys, and a plurality of musical tone instruction devices that are provided respectively for the plurality of keys and each instruct generation and damping of a musical tone in response to depression of a corresponding one of the plurality of keys, wherein the first sensor comprises a sensor driven by the corresponding one of the keys, for detecting release of the corresponding one of the keys, and the second sensor comprises a sensor driven by a corresponding one of the mass members, for detecting depression of the corresponding one of the keys.
The above and other objects of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.